The boat uses a combination of solar panels, wind turbines, and a hydrogen fuel cell system

Energy Observer, a self-fueled boat, has embarked on a six-year voyage around the world in hopes of testing energies of the future in extreme environments and serving as a model for emissions-free travel through technological innovation.

The $5.25m (£4m) ship, originally used for open-sea sailing races, left Paris on 15 July and is headed towards the Atlantic. It will depend on clean energy throughout the journey, which will span across 50 countries and have 101 stopovers.

The 100-foot-long vessel uses a combination of solar panels, wind turbines and a hydrogen fuel cell system to power its engine. It deploys Sun and wind energy during the day and taps into hydrogen reservoirs during the night. The Energy Observer plans to open a path of autonomous navigation with hydrogen produced on board through electrolysis of sea water, without greenhouse gas emissions. In other words, more than a mode of transport, the boat is serving as a laboratory of the new energy model.

On the website of the project titled "The first hydrogen ship around the world", Captain Victorien Erussard said: "There is no silver bullet to fight against global warming: there are solutions, which we must learn to make work between them. This is what we do with Energy Observer: to bring together the energies of nature, but also of our society, bringing together around this boat, the know-how of companies, laboratories, start-ups and institutions." Erussard will be leading the expedition along with naval explorer Jérome Delafosse.

The Energy Observer team plans to dock in "capitals already engaged in the energy transition, places with ecosystem threatened, major international events, Unesco World Heritage sites, places destined to disappear, and nature reserves".